Method and apparatus for photoelectric rating of throttle tube deposits



Dec. 14, 1965 H. R. WEBER 3,223,844 1 METHOD AND APPARATUS FOR PHOTOELECTRIC RATING OF THROTTLE TUBE DEPOSITS Filed March 50, 1962 2 Sheets-Sheet l "A 45- x r L9 9 m3 59 V g;

H. R. WEBER METHOD AND APPARATUS FOR PHOTOELECTRIC RATING OF THROTTLE TUBE DEPOSITS Dec. 14, 1965 2 Sheets-Sheet 2 Filed March 30, 1962 3,223 844 METHOD AND APPARATlfJS FOR PHOTOELEQTRIC RATING F THROTTLE TUBE DEPOSITS Harry R. Weber, Haddonfield, N.J., assignor to 0cony Mobil Oil Company, End, a corporation of New York Filed Mar. 30, 1962, Ser. No. 183,914 7 Claims. ((11. 250-218) This invention relates to evaluating gasoline detergent additives and more particularly to a method and apparatus for photoelectrically rating deposits in a carburetor throttle tube or body.

Gasolines contain detergent additives to prevent carburetor throttle tube deposits. These deposits, if they are going to occur, usually build up during periods of idling. The deposits are then wholly or partly swept away during periods of acceleration depending upon the effectiveness of the detergent additives in the gasoline. A test has been developed to determine the effectiveness of the additives in eliminating these deposits. In this test, a conventional automotive gasoline piston engine is equipped with a special carburetor having a glass throttle tube. The piston rings of the engine are altered to permit blowby into the crank case and the blowby is recycled in controlled amounts into the carburetor air. The engine is operated for a period of eight hours at idle speed, with a short full throttle acceleration every three minutes. This procedure simulates the road conditions which exist when an automobile is in a line of traffic for a long period of time. Under these road conditions the worst deposits occur. After the engine has been operated in this manner for the eight-hour road simulation test, the glass throttle tube is removed from the carburetor and examined for deposits and the amount of the deposits is rated. One way of performing the rating is to place a transparent sleeve over the throttle tube marked off in sections and then rate the deposits coinciding with each section in accordance with the following table.

In this manner an evaluation of the effectiveness of the detergent additives in the gasoline can be obtained. However, since rating the deposits in this manner is visual and depends upon the judgment of the person examining the throttle tube, the accuracy of the rating suffers and different evaluations can be obtained from the same throttle tube deposits when they are examined by different people.

The present invention provides a photoelectric system for examining the glass throttle tube and rating deposits, thus eliminating a large part of the human error and inconsistency in the above described method of rating. The rating and resulting evaluation by the system of the present invention are therefore more accurately determined.

According to the present invention, the glass throttle tube is placed in a photoelectric examining chamber in which light is caused to pass through specifically defined areas in the throttle tube where the deposits occur. The amount of light passing through each specifically defined area is measured by a photoelectric cell. In this manner the deposits are rated and an accurate evaluation of Patented Dec. 14, 1965 the effectiveness of the detergent additives in the gasoline is obtained. Because of the pattern in which the deposits occur on the glass throttle tube, the size of the specifically defined areas varies with their angular position on the throttle tube. This variation will in turn cause a variation in the amount of light passing through the specifically defined areas. This variation is auto matically compensated by electronic-averaging in the system of the present invention.

Accordingly, an object of the present invention is to provide an improved system for evaluating the effectiveness of detergent additives in fuel.

Another object of the present invention is to provide a more accurate evaluation of the effectiveness of detergent additives in fuel.

A further object of this invention is to provide an improved method and apparatus for rating deposits on throttle tubes.

A still further object of this invention is to provide a more accurate rating of deposits on throttle tubes.

A still further object of this invention is to provide a system for photoelectrically rating deposits on throttle tubes.

Further objects and advantages of the present invention will become readily apparent as the following detailed description of the invention unfolds and when taken in conjunction with the drawings, wherein:

FIG. 1 shows a view in partial section of the glass throttle tube, which is examined by the method and apparatus of the present invention, with the throttle plate mounted in the throttle tube;

FIG. 2 shows sectional views of the throttle tube with the throttle plate removed illustrating a typical pattern of deposition on the throttle tube after it has been through the eight-hour road simulation test;

FIG. 3 is a view in partial section illustrating the throttle tube with a black nylon block inserted therein in accordance with the system of the present invention;

FIG. 4 illustrates the examining apparatus of the present invention with the front panel removed and a portion of the front plate of the examining chamber broken away;

FIG. 5 is a view in partial section of the examining apparatus of the present invention; and

FIG. 6 is a schematic diagram of the electrical circuit used in the apparatus of the invention.

FIG. 1 illustrates the throttle tube with the throttle plate mounted therein as it is when the throttle tube is in use in a carburetor. In FIG. 1 the throttle plate is designated by the reference number 11 and the throttle tube is designated by the reference number 13. The throttle tube 13 is made of Pyrex glass or other heat-resistant transparent material. When it is used in a carburetor in the test procedure, it simply replaces the conventional throttle tube in the carburetor. The Pyrex throttle tube 13 is made of precision tubing with its ends parallel and square with the bore of the tube. Throttle shaft holes 15 directly across from each other are defined in the Walls of the throttle tube 13. The center line of the shaft holes 15 intersects and is perpendicular to the center line of the bore of the tube 13. All of the sharp corners on the throttle tube 13 are chamfered. The throttle plate 11 has a shaft 17 which is pivotally mounted in the throttle shaft holes 15 when the plate 11 is mounted in the tube 13. When the engine fed by the carburetor using the throttle tube 13 is at idle, the throttle plate 11 will be in the position shown in FIG. 1. In this position the throttle plate will contact the inner Walls of the throttle tube 13 along a fixed line which is in the form of an ellipse. This line is designated in FIG. 2 by the reference number 19. Deposits, if they are to occur, will form on the wall of the tube 13 below the line 19. These 3 deposits, which are designated by the reference number 21 in FIG. 2, will physically define the line 19 by their upper boundary. As shown in FIG. 2, the deposits 21 taper or flag out proceeding away from the line 19.

The purpose of the apparatus of the present invention is to measure the amount of the deposits on the wall of the throttle tube. The amount of deposits on the wall of the throttle tube 13 will depend upon the effectiveness of the additives for preventing carburetor throttle tube deposits, which additives were in the gasoline which was used when the throttle tube was run through the eighthour simulated road test. Thus the apparatus and method of the present invention provide an indication of the effectiveness of these additives.

In accordance with the present invention, as shown in FIG. 3, a generally cylindrically shaped opaque black nylon block 25 is inserted into the upper end of the throttle tube 13. The dimension of the outer cylindrical wall of the block 25 is such that it easily slides within the glass tube 13. An annular groove 27 is defined in the outer cylindrical wall of the block 25 and an O-ring 29 is placed in this groove 27. The O-ring 29 holds the block 25 and the glass tube 13 together. An aluminum knob 31 is mounted on the end of the block 25. The knob 31 is substantially wider than the block 25 and is provided with a fiat surface 33 perpendicular to the axis of the block 25. The block 25 is inserted into the tube 13 until the fiat surface 33 abuts against the end of the tube 13. The end of the block 25 which is inserted into the tube 13 ends in a flat surface 35 which slants at an angle of 15 47' with respect to a plane perpendicular to the axis of the block 25. This angle of 15 47 is the same angle which the throttle plate 11 makes with a plane perpendicular to the axis of the throttle tube 13 when the throttle plate 11 is in its idle position as shown in FIG. 1. Therefore the outer edge of the slanted surface 35 defines an ellipse which is substantially congruent with the line 19. When the block 25 is inserted in the tube 13 it is angul-arly positioned with respect to the tube 13 so that the ellipse defined by the outer edge of the surface 35 lies along the line 19, or in other words so that the block 25 completely covers the surface of the tube 13 above the line 19.

The assembly of the tube 13 and the block 25 is inserted into a photoelectric examining chamber 37 as shown in FIGS. 4 and 5. The photoelectric examining chamber 37 is located in an instrument housing comprising a top plate 39, side plates 41, a back plate 43 and a front panel, which has been removed in FIG. 4 for purposes of illustration. The photoelectric examining chamber is defined by the top plate 39, the side plates 41, the back plate 43, a bottom plate 45 and a front plate 47, which has been broken away in FIG. 4 to illustrate the interior of the examining chamber 37. The bottom plate 45 of the chamber 37 is spaced substantially above the bottom of the housing and the front plate 47 is spaced behind the front panel of the housing. A circular aperture is defined in the center of the top plate 39 and the assembly of the throttle tube 13 and block 25 is inserted into the chamber 37 through this circular aperture. The knob 31 remains above the top plate 39 with the surface 33 resting against the top plate 39. Positioned in the center of the chamber 37 coaxial with the circular aperture in the top plate 39 is an opaque black nylon tube 49. The inner diameter of the tube 49 is slightly wider than the outer diameter of the throttle tube 13 so that when the throttle tube 13 is inserted into the chamber 37, it is surrounded by the black nylon tube 49, which extends from the top to the bottom of the chamber 37. An annular aperture is defined in the bottom plate 45 coaxial with the tube 49. A light source comprising a lamp 51 extends up through the aperture in the bottom plate 45 into the tube 49. The block 25 is provided with a recess 52, into which the lamp 51 extends. The lamp 51 is energized from a socket 53 mounted on a bracket 55, which in turn is mounted on the bottom plate 45 beneath the chamber 37. The part of the lamp 51 between the chamber 37 and the bracket 55 is surrounded by a black nylon collar 57 which is cemented to the tube 49 thereby completely enclosing the lamp 51. The tube 49 abuts against the bottom plate 45 so that the chamber 37 is completely closed off and isolated from stray light. A pair of photoelectric tubes 59 are mounted in the chamber 37 one on each side of the black nylon tube 49. The tubes 59 are mounted on the bottom plate 45. A pair of vertically disposed rectangular slots 61 are defined through the wall of the tube 49, one facing each of the photoelectric tubes 59. The slots 61 are diametrically opposite to each other with respect to the axis of the tube 49. When the lamp 51 is energized, light will pass through those portions of the throttle tube 13 which are opposite the slots 61 and which are not covered by the nylon block 25. Since the nylon block 25 covers or blocks out that portion of the throttle tube 13 above the line 19, the light passing through the slots 61 will only pass through those portions of the throttle tube 13 opposite the slots 61 which are below the line 19. Thus the light passing through the throttle tube 13 and the slots 61 is limited to the portion of the tube where the deposits 21 are formed. The light passing through the slots 61 irradiates the photoelectric tubes 59.

The amount of light irradiating each of the tubes 59 will depend upon the amount of deposit on those portions of the throttle tube 13 opposite the slots 61. If a heavy deposit completely covers that portion of the throttle tube 13 below the line 19 and opposite the one of the slots 61, then very little light will pass through this slot and irradiate the photoelectric tube 59 opposite this slot. On the other hand, if only a light deposit covers that portion of the throttle tube 13 opposite one of the slots 61, then a relatively large amount of light will pass through this slot and irradiate the photoelectric tube 59 opposite this slot. Thus the amount of light passing through the slots 61 and irradiating the tubes 59 will vary with the amount of deposit on the throttle tube 13 opposite the slots 61. However, the amount of light passing through just one of the slots 61 will not provide a good indication of the amount of deposit on the throttle tube 13 opposite such slot because the length of the slot which is below the line 19 will vary with the angular position of the throttle tube 13 in the black nylon tube 49. As pointed out above, the deposits only occur on the throttle tube 13 below the line 19 and the light from the lamp 51 is prevented from passing through the throttle tube 13 above the line 19 by the black nylon block 25. Thus because the length of the slot which is below the line 19 varies with the angular position of the throttle tube 13, the amount of light passing through the slot 61 will vary with the angular positon of the throttle tube 13 as well as with the amount of deposit on the throttle tube 13. It will be noted, however, that when the length of one of the slots 61 below the line 19 is long, the length of the other slot 61 below the line 19 will be short, and vice versa. If the average of the irradiation of each of the tubes 59 is measured, then a good indication of the amount of deposit on the throttle tube 13 opposite the slots 61 will be obtained. FIG. 6 shows a circuit for performing such a measurement.

As shown in FIG. 6, the lamp 51 is adapted to be energized by an A.C. source 71. One side of the AC. source 71 is grounded, and the other side of the AC. source is connected through a power switch 73, a fuse 75, a lamp switch 77, a variable resistor 79 and a resistor 81 to the lamp 51 which completes the circuit to ground. By means of the variable resistor 79, the intensity of the light provided by the lamp 51 can be adjusted. The junction between the fuse 75 and the switch 77 is connected to ground through a series circuit of a resistor 83 and an indicating lamp 85. The indicating lamp 85 is mounted on the front panel of the instrument and will be energized when the power switch 73 is closed, thus providing an indication of when the power to the system is turned on. A series circuit of a resistor 87 and an indicating lamp 89 is connected from between the junction of the switch 77 and the variable resistor 79 to ground. The lamp 89 is mounted on the front panel of the instrument and indicates when the switch 77 is closed applying power to the lamp 51. The primary winding 91 of a transformer 93 is connected from between the junction of the fuse 75 and the switch 77 to ground. Thus when the power switch 73 is closed, AC. power will be applied across the primary winding 91 of the transformer 93. Secondary winding 95 of the transformer 93 is connected to energize the two photocells 59. One side of the secondary winding 95 is connected to the anodes of the photocells 59 and the other side of the secondary winding 95 is connected to the movable contact of a potentiometer 97. One end terminal of the potentiometer 97 is connected to an end terminal of a potentiometer 99 and the other end terminal of the potentiometer 97 is connected to one end terminal of a potentiometer 101. The other end terminal of the potentiometer 99 is connected through a resistor 103 to the junction between the secondary winding 95 and the anodes of the photoelectric tubes 59, and the other end terminal of the potentiometer 101 is connected through a resistor 105 to the junction between the secondary winding 95 and the anodes of the photocells 59. The cathode of one of the photocells 59 is connected through a resistor 107 to the movable contact of the potentiometer 99 and the cathode of the other photocell 59 is connected through a resistor 159 to the movable contact of the potetiometer 101. Thus a portion of the AC. voltage generated in the secondary winding 95 of the transformer 93 will be applied across the photocells 59 through the potentiometers 97, 99, and 101 and the resistors 107 and 109. On each half cycle of the voltage generated in the secondary win-ding 95 in which the anodes of the photocells 59 are made positive with respect to their cathodes, each photocell will conduct a current proportional to the amount of light with which such photocell is irradiated. The junction between the cathode of the photocell 59 and the resistor 107 is connected to the grid of a triode 111 and the junction between the cathode of the other photocell 59 and the resistor 159 is connected to the grid of a triode 113. The triodes 111 and 113 are combined in a double triode. The junction between the resistor 1G3 and the potentiometer 99 is connected to the cathode of the triode 111 and the junction between the resistor 105 and the potentiometer 101 is connected to the cathode of the triode 113. The plates of the triodes 111 and 113 are connected together and through an ammeter 115 to the junction between the secondary winding 95 and the anodes of the photocells 59. The arnmeter 115 is shunted by a resistor 117.

On the half cycles of the voltage generated in the secondary winding 95 in which the anodes of the photocells 59 are made positive wit-h respect to their cathodes, the plates of the triodes 111 and 113 will also be made positive with respect to their cathodes. These triodes 111 and 113 will therefore conduct currents proportional to the signal voltages applied to their grids, and the current flowing through the amrneter 115 Will be proportional to the average of these two currents since the plates of the triodes 111 and 113 are connected together and through the ammeter 115. The voltage applied to the grid of the triode 111 will be proportional to the current flowing through one of the photocells 59 and the voltage applied to the grid of the triode 113 will be proportional to the current flowing through the other photocell 59. Thus the current flowing through the ammeter 115 will be proportional to the average of the combined irradiation of both of the photocells 59. Therefore when the lamp 51 is energized by the closure of the switches 73 and 77, the ammeter 115 will provide an accurate indication of the amount of deposit on those portions of the glass throttle tube 13 opposite the slots 61. The movable contacts of the resistors 99 and 101 are ganged together and they provide a dark current or zero adjustment. The movable contact of the potentiometer 97 is used to balance the circuit.

The procedure for examining the deposits on the Pyrex glass throttle tube 13 with the instrument described above is to examine the deposited material at 20 intervals through 180. For this purpose the top plate 39 is provided with index markings at 20 intervals around the knob 31 and a pointer 119 is provided on the knob 31. When the throttle tube 13 and the block 25 have been inserted into the chamber 37, the pointer 119 is aligned with one of the reference marks on the plate 39. After the lamp 51 has been energized and the circuit has been properly adjusted, the reading of the ammeter is recorded. Then the knob 31 is rotated until the next index marker on the top plate 39 is opposite the pointer 119 and the indication of the a-mmeter 115 is again read and recorded. This process is repeated until nine readings have been taken and the knob 31 has been rotated through At this time 360 of the Pyrex tube 13 below the line 19 will have been examined and an indication of the effectiveness of the additives in the gasoline to prevent throttle tube deposits will be obtained.

The above description is of a preferred embodiment of the invention, and many modifications may be made thereto without departing from the spirit and scope of the invention, which is defined in the appended claims.

What is claimed is:

1. A deposit rating apparatus comprising a transparent throttle tube, said throttle tube having a throttle plate which is adapted to contact the inner wall of said throttle tube along a predetermined line within said throttle tube, means defining an examining chamber, an opaque tube within said chamber having a transparent opening defined through the wall thereof and adapted to receive said throttle tube, means to pass light through said opening and through said throttle tube received by said opaque tube, a photocell positioned to be irradiated by light passing through said opening and through said throttle tube, and means to block said light from passing through said throttle tube on one side of said predetermined line.

2. A deposit rating apparatus as recited in claim 1 wherein said means to block light comprises an opaque block adapted to be inserted within said throttle tube.

3. A deposit rating apparatus comprising a transparent throttle tube having a throttle plate adapted to contact the inner wall of said throttle tube along a predetermined line, an opaque tube having an opening defined therein adapted to telescope with said transparent throttle tube, an opaque block adapted to telescope with said opaque tube and said transparent throttle tube so as to cover the wall of said throttle tube on one side of said predetermined line, means to pass light through said opening in said opaque tube and through said transparent throttle tube, and means to measure the amount of light passing through said transparent opening and said transparent throttle tube.

4. A deposit rating apparatus comprising a transparent throttle having a throttle plate adapted to contact the inner wall of said throttle tube along a predetermined line, an opaque tube having transparent openings on the opposite sides thereof and adapted to telescope with said transparent throttle tube, means to pass light through said transparent openings and through said transparent throttle tube, and means to measure the amount of light passing through said transparent openings and through said transparent throttle tube and indicate the average thereof.

5. A method of evaluating the effectiveness of detergent additives in gasoline comprising the steps of: providing a transparent throttle tube in the carburetor of a gasoline engine, fueling said engine with gasoline containing said additives, operating said engine with said transparent throttle tube provided in the carburetor thereof while the engine is fueled with the gasoline containing said additives,

7 then irradiating the wall of said throttle tube with light, and photoelectrically detecting the amount of light passing through the Wall of said throttle tube.

6. A method of evaluating the effectiveness of detergent additives in gasoline comprising the steps of: providing a transparent throttle tube in the carburetor of a gasoline engine, fueling said engine with gasoline containing said additives, operating said engine With said transparent throttle tube provided in the carburetor thereof while the engine is fueled with the gasoline containing said additives, then irradiating the wall of said transparent throttle tube with light, restricting the light passing through said transparent tube into an examining area to the light irradi ating a limited area of said tube, detecting the amount of light passing through the wall of said throttle tube into said examining area, and successively changing said limited area.

7. A method of evaluating the effectiveness of detergent additives in gasoline comprising the steps of: providing a transparent throttle tube in the carburetor of a gasoline engine, said throttle tube having a throttle plate adapted to contact the inner Wall of said throttle tube along a predetermined line, fueling said engine with gasoline containing said additives, operating said engine with said transparent throttle tube provided in the carburetor thereof While the engine is fueled With the gasoline containing said additives, then irradiating the wall of said throttle tube With light, limiting the light passing through said throttle tube to an examining area to that which irradiates'the Wall of said throttle tube on only one side of said predetermined line, and detecting the amount of light passing through the wall of said throttle tube to said examining area.

References Cited by the Examiner UNITED STATES PATENTS 2,501,599 3/1950 Eltenton et al. 250218 2,898,803 8/1959 Morrison 8414 2,982,169 5/1961 Enright 8414 RALPH G. NILSON, Primary Examiner.

WALTER STOLWEIN, Examiner. 

1. A DEPOSIT RATING APPARATUS COMPRISING A TRANSPARENT THROTTLE TUBE, SAID THROTTLE TUBE HAVING A THROTTLE PLATE WHICH IS ADAPTED TO CONTACT THE INNER WALL OF SAID THROTTLE TUBE ALONG A PREDETERMINED LINE WITHIN SAID THROTTLE TUBE, MEANS DEFINING AN EXAMINING CHAMBER, AN OPAQUE TUBE WITHIN SAID CHAMBER HAVING A TRANSPARENT OPENING DEFINED THROUGH THE WALL THEREOF AND ADAPTED TO RECEIVE SAID THROTTLE TUBE, MEANS TO PASS LIGHT THROUGH SAID OPENING AND THROUGH SAID THROTTLE TUBE RECEIVED BY SAID OPAQUE TUBE, A PHOTOCELL POSITIONED TO BE IRRADIATED BY LIGHT PASSING THROUGH SAID OPENING AND THROUGH SAID THROTTLE TUBE, AND MEANS TO BLOCK SAID LIGHT FROM PASSING THROUGH SAID THROTTLE TUBE ON ONE SIDE OF SAID PREDETERMINED LINE. 